Instruments for sealing and cutting blood vessels are known in principle. An example is disclosed in German publication DE 602 26 015 T2.
These instruments comprise an elongated shaft with a tool arranged at its distal end with two arms for clamping a blood vessel. In addition, a longitudinally adjustable knife is also arranged there to enable a gripped and coagulated vessel to be severed. A handle with an actuation mechanism is arranged at the proximal end of the shaft such that the arms can be closed and the knife can be actuated. The arms are designed as electrodes that can heat up the vessel clamped between them and fuse the vessel walls by coagulation.
When cutting through blood vessels, it must be ensured that the ends of the severed vessel are reliably sealed; further conditions have to be satisfied to do so. For example, any damage to surrounding tissue must be avoided. The sealing of vessels should be largely independent of the size of the vessels and the thickness of the vascular walls. Consideration must furthermore be given to the confined space available, particularly if the instrument is to be used for endoscopic or laparoscopic applications.